Update xrdp_keyboard.ini to handle Swiss French

[Frédéric Bourqui]

Hi,
I did a really small patch for xrdp upstream. It was pulled and merged in version 0.9.6.
Debian as just accepted 0.9.6 in buster (testing).

I understand you will not update to 0.9.6 for the 18.04 LTS, but could you import my patch in current 0.9.5 it has no impact whatsoever on other part of the package, it just support for Swiss-French keyboard, 3 lines added to xrdp_keyboard.ini

Upstream issues:
* https://github.com/neutrinolabs/xrdp/pull/1053/
* https://patch-diff.githubusercontent.com/raw/neutrinolabs/xrdp/pull/1053.patch

The patch add the missing Swiss French rdp_layout_ definitions, ch(fr) in X11.

18.04 LTS will be used for a long time, and it would help all people working with Swiss-French keyboard that needed to use trick to have consistent behavior with xrdp, keyboard would reset to US upon re connection on an existing xrdp session.

Side note:
This could be back-ported to all older version of xrdp as Swiss French keyboard hardware was never supported. Could be applied to xrdp package of 14.04, 16.04, 17.10 and 18.04.